PLATE XIY. 
Figs. 1, la. — Hypanthea aggregata (p. 26). 
Fig. 1. — A colony ; natural size. 
Fig. la . — Portion of a colony; magnified 15 diameters. 
a. Gonangia occupied by the solitary sporosac surrounded by a network of tubes into which the 
blastostyle has become broken up. 
b. Empty gonangia. 
Figs. 2, 2 a. — Hypanthea hemispherica (p. 27). 
Fig. 2. — A colony ; natural size. 
Fig. 2 a . — Portion of a colony ; magnified 15 diameters. 
